Refrigerator of the absorption type



y 1932- A. SILBERNAGEL 1 1,858,434

REFRIGERATOR OF THE ABSORPTION TYPE Filed Oct. 26. 1929 jnugntuavwfidol ah Silbgrnagei Patented July 19, 1932 PATENT OFFICE ADOLF SILBERNAGEL, 0F BASEL, SWITZERLAND REFRIGERATOR OF THE ABSORPTION TYPE Application filed October 26, 1929, Serial No. 402,657, and in Switzerland November 12, 1928.

In absorption refrigerators, such as those operating with ammonia and water, notwithstanding the presence of a water separator, a small amount of water always reaches the 6 vaporizer during the heating period, and has to be returned to the absorber-generator if the efliciency is not to appreciably diminish. Hitherto this water has been returned to the absorber-generator by means involving valves or cocks, or by tube systems which act automatically but only operate when no great amount of fluid has to be lifted.

This invention relates to an absorption refrigerator in which any amount of fluid can be drawn up from the vaporizer and returned to the absorber-generator automatically without the use of valves or cocks, so that a small amount of water can be taken up within a single cooling period and a larger amount in three or four successive cooling periods, whilst the condensed ammonia or refrigerant can only run onto the upper layer of the liquid without intermixing therewith.

A refrigerator according to the invention may be transported or stored in any position, and will operate normally when restored to its normal position and set in action. Accord ing to the invention the refrigerator has a single through connecting tube between the absorber-generator and the vaporizer, extending from the lower part of the absorber-generator and reaching by an extension to the bottom of the vaporizer. a small vessel open at the top being combined with said tube extension within the vaporizer and having a minute opening at its lower part, so as to allow the outlet of condensed refrigerant upon the liquid in the vaporizer, whilst preventing a p, return flow thereof when liquid is returned W through said tube from the vaporizer to the absorber. Thus the liquid can be returned from the vaporizer to the absorber without lifting condensed refrigerant, and this without any valve or cock arrangement.

The invention is diagrammatically illustrated in the accompanying drawing;

Figure 1 is a section of a refrigerator and Figures 2. 3 and 4 show alternative constructions of the vaporizer.

In Fi re l the heating and cooling tubes of the absorber-generator a are indicated at a o The absorber-generator a is connected by a single through tube It with the vaporizer The tube It starts from the lower part of the generator at and is prolonged by an extension 6 dipping into the deepest part of the vaporizer f. Within the vaporizer the part of the tube it next the extension 6 enters a small vessel 6 associated to the extension 0, open at the top to communicate freely with the interior of the vaporizer.

The tube extension 6 is, in Figure 1, sit uated within a well 70 depending from the lower part of the vaporizer; or it may as in Figures 2, 3 and 4 end in a loop or ring exposed to the atmosphere, or in a straight tube similarly exposed. In the constructions of Figures 2 to 4: vaporization is more vigorous in the extension 6 than in the vaporizer vessel, so that a sort of lift-pumping effect results. In all cases, the tube extension 6 is closed at its upper end, but has lateral openings in the wall of its part protruding into the vessel 6 The lower part of the vessel 6 is provided with a minute orifice Z through which the liquid ammonia or refrigerant coming from the condenser may flow onto the liquid within the vaporizer, without mixing with the absorption fluid in the lower part of the vaporizer.

During the boiling period the ammonia vapor collecting in the riser b flows through the tube 2' to a control vessel 0 which. also acts as a water separator. The water vapor carried off by the ammonia is retained by the cold fluid in thecontrol vessel 0 and passes through the overflow 0" and tube It back to the generator c. The dry ammonia flows from the control vessel 0 through the condenser (Z and leaves it as a liquid, passing through the tube 71, to the vaporizer f where it flows out through the minute orifice Z into the space surrounding the vessel 0 and onto the liquid contained in the vaporizer.

Since some absorption liquid; will have remained in the vaporizer at the end of the preceding cooling period, or will have reached the vaporizer through the apparatus having been overturned, the liqu d in the vaporizer will finally rise above the level 9 during the boiling period and will cover the mouth of the tube It within the vessel 6 so as to produce a hydraulic closure of the tube h.

Consequently at the beginning of the cooling period the tube h does only suck up liquid into the generator from the lower part of the vaporizer through the tube extension 6, whilst the refrigerant at the outside of the vessel 6 cannot flow back thereinto on account of the minute cross section of the opening Z with respect to the large cross section of the operating tube 70. The back'flow of the absorption liquid from the vaporizer continues until the mouth of the tube It is uncovered. The liquid thus lifted comes from the lowest part of the vaporizer where the absorption liquid from the last cooling process has collected.

If the tubeextension e is immediately surrounded by the outer air and is in the form of a loop or ring (Figures 2, 3 and 4) or of a'straight tube, absorption liquid will continue to be drawn up even when the liquid level in the vaporizer has fallen below 9. For bubbles of ammonia'will form in the loop or ring or straight tube, and will carry up the liquid as in a liquid lift pump.

As the tube It leads directly to the generator, very little ammonia is necessary for normal operation to remove the undesired liquid from the vaporizer to the generator.

What I claim is 1. In a refrigerator of the absorption type, the combination of an absorber-generator, a vaporizer, a condenser, a control vessel serving as water separator between the upper part of the absorber-generator and the condenser, a single tube connecting the absorbergenerator to the vaporizer, means connect a ing the water space of said control vessel'to' said tube, means connecting the condenser to said tube, a small open vessel within the vaporizer, within which ends said tube, a tube extension extending from said vessel to the lowest part of the vaporizer and projecting at its upper end up to a certain height into said vessel, the latter being provided in its lower part below the upper end of said tube extension with a small opening for the discharge of condensed refrigerant upon the liquid in the vaporizer, substantially for the purpose described.

2. In a refrigerator of the absorption type, the combination of an absorber-generator, a vaporizer, a condenser and a single tube connecting the absorber-generator to the vaporizer, means connecting the condenserto said tube, a small open vessel within the vaporizer, within which ends said tube, a tube extension extending from said vessel to the lowest part of the vaporizer, having a part exposed to outer air and projecting at its upper end into said vessel, the latter being provided in its lower part with a small opening for the discharge of condensed refrigerant upon the liquid in the vaporizer, substantially for the purpose described.

3. In a refrigerator of the absorption type, the combination of an absorber-generator, a vaporizer, a condenser, and a tube connectin the absorberenerator to the vaporizer, t e condenser .eing connected to said tube, a small open vessel within the vaporizer, within which the said tube ends, and being provided in its lower part with a small opening for the discharge of condensed refrigerant upon the liquid in the vaporizer, and a tube extension extending from said vessel to the lowest part of the vaporizer and projecting into and communicating at its upper end with said vessel, the portion thereof exterior of the vessel being freely exposed to the medium in said vaporizer so that, after the cessation of boiling and owing to the higher temperature prevailing in said medium than in said tube, a gas development takes place in said tube, producing a great, pump-like action on the contents within the tube and vessel.

In witness whereof I have hereunto signed my name this 16th day of October, 1929.

ADOLF SILBERNAGEL. 

